Drawing-free die for synchronous pulley

Abstract

The utility model belongs to the technical field of dies, and particularly relates to a draft-free die for a synchronous pulley, which comprises a movable module, a fixed module is arranged on one side of the movable module, a surrounding structure is arranged on the movable module and comprises a turntable and a plurality of first guide grooves, the turntable is rotatably connected onto the movable module, and the first guide grooves are arranged on the turntable. The movable module is slidably connected with a plurality of sliding blocks, one end of each sliding block is fixedly connected with a first guide shaft, each first guide shaft extends into the corresponding adjacent first guide groove and is slidably connected with the rotating disc, the other end of each sliding block is fixedly connected with a check block, the adjacent check blocks abut against each other, and the fixed module is provided with a pushing structure; and during mold opening, the multiple stop blocks move away from the synchronous belt wheel, so that demolding of the synchronous belt wheel can be achieved without pattern draft, and high-precision die-casting forming of the synchronous belt wheel is achieved.

Description

A draft-free die for timing pulleys Technical Field

[0001] This utility model belongs to the field of mold technology, specifically a non-draft mold for synchronous belt pulleys. Background Technology

[0002] Synchronous pulleys are transmission components used in conjunction with synchronous belts. They transmit power through the meshing of belt teeth and pulley grooves, avoiding the slippage problem of traditional belt drives and ensuring synchronization. This meshing transmission method combines the advantages of belt drives, chain drives, and gear drives, and is especially suitable for low-speed, high-torque scenarios. In the die-casting production of plastic synchronous pulleys, traditional molds are usually designed with a certain angle of draft angle to facilitate demolding.

[0003] However, the presence of draft angles can cause deviations in the axial dimensions of the synchronous pulley, affecting its meshing accuracy with the synchronous belt and reducing transmission efficiency and stability. For some applications such as precision instruments and high-end automated equipment with extremely high transmission accuracy requirements, traditional die-casting molds with draft angles are difficult to meet the needs.

[0004] Therefore, it is necessary to design a mold without draft angle. Summary of the Invention

[0005] Based on this, this solution provides a draft-free mold for synchronous belt pulleys, which eliminates the need for draft angles, thereby enabling high-precision die casting of synchronous belt pulleys.

[0006] The technical solution of this utility model to solve the above-mentioned technical problems is as follows:

[0007] A draft-free mold for a timing pulley includes a moving module, a fixed module on one side of the moving module, and an enclosing structure on the moving module. The enclosing structure includes a turntable and a first guide groove. The turntable is rotatably connected to the moving module, and the turntable has multiple first guide grooves. Multiple sliders are slidably connected to the moving module. One end of each slider is fixedly connected to a first guide shaft, which extends into the interior of an adjacent first guide groove and is slidably connected to the turntable. The other end of each slider is fixedly connected to a stop block, and adjacent stops abut against each other. The fixed module has a pushing structure.

[0008] Optionally, in one embodiment of the present invention, the moving module is provided with a plurality of springs, one end of the springs being fixedly connected to an adjacent slider, and the other end of the springs being fixedly connected to the moving module.

[0009] Optionally, in one embodiment of the present invention, the plurality of first guide grooves are arranged in a circular array about the rotation center of the turntable, and there is a certain angle between the orientation of the first guide grooves and the sliding direction of the slider.

[0010] Optionally, in one embodiment of the present invention, the cross-section of the slider is a dovetail-shaped structure, one end of the plurality of stops abuts against the fixed module, and the other end of the plurality of stops abuts against the moving module.

[0011] Optionally, in one embodiment of the present invention, the pushing structure includes a connecting sleeve and a second guide shaft. The fixed module is fixedly connected to the connecting sleeve, and two second guide shafts are fixedly connected to the connecting sleeve. Two connecting plates are fixedly connected to the turntable. The connecting plates are provided with second guide grooves. The second guide shafts extend into the interior of adjacent second guide grooves and are slidably connected to the connecting plates. The moving module is provided with a sliding groove, and the connecting plates and the sliding grooves are slidably engaged.

[0012] Optionally, in one embodiment of the present invention, the center of the turntable and the center of the connecting sleeve are on the same straight line, and the two second guide shafts are distributed in a circular array about the center of the connecting sleeve.

[0013] Optionally, in one embodiment of the present invention, the two connecting plates are arranged in a circular array about the center of the turntable, and the two second guide grooves are arranged in a circular array about the center of the turntable.

[0014] Optionally, in one embodiment of the present invention, four guide posts are fixedly connected to the moving module, and four guide sleeves are fixedly connected to the fixed module. The guide posts are inserted into the interior of adjacent guide sleeves and slide in cooperation with the guide sleeves.

[0015] Optionally, in one embodiment of the present invention, the moving module is provided with four mounting holes, and the stationary module is provided with four mounting holes.

[0016] Compared with the prior art, the non-draft mold for timing pulleys provided by this utility model has the following characteristics:

[0017] During the mold opening process, the stop block actively and synchronously retracts radially inward through the turntable, the first guide groove, the first guide shaft, and the slider, completely detaching from the side wall of the synchronous pulley after molding. This avoids the need to design draft angles on the side wall of the part, which helps to improve the geometric accuracy and dimensional consistency of the product.

[0018] When the mold is closed, the blocks abut against each other, and their ends abut against the moving module and the fixed module respectively. The protrusion in the middle of the fixed module engages with the moving module to form a closed cavity with precise positioning, which ensures the shape and dimensional accuracy of the molded parts.

[0019] The connecting sleeve, second guide shaft, connecting plate, and second guide groove separate the linear motion of the moving module and the stationary module during mold opening. The motion is converted into the rotational motion of the turntable by sliding in the inclined second guide groove through the second guide shaft. The demolding action is directly driven by the power of mold opening, without the need for an additional power source. This simplifies the mold structure, reduces costs, and improves the coordination and efficiency of the action.

[0020] After the mold opening is completed and the second guide shaft disengages from the second guide groove, the spring force can automatically push the slider and its stop back to the initial specific position, so that the second guide shaft can accurately and smoothly re-enter the second guide groove when the mold closes again, ensuring the reliability and continuity of the mold cycle operation. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 is a schematic diagram of the overall structure of Embodiment 1 of this utility model;

[0023] Figure 2 is a schematic diagram of the connection structure between the guide post and the guide sleeve in Embodiment 1 of this utility model;

[0024] Figure 3 is a schematic diagram of the connection structure between the connecting plate and the second guide groove in Embodiment 1 of this utility model;

[0025] Figure 4 is a schematic diagram of the connection structure between the connecting sleeve and the second guide shaft in Embodiment 1 of this utility model;

[0026] Figure 5 is a schematic diagram of the connection structure between the slider and the stop in Embodiment 1 of this utility model.

[0027] Reference numerals in the attached drawings: Moving module 1, Fixed module 2, Enclosing structure 3, Turntable 301, First guide groove 302, First guide shaft 303, 304, Slider; 305, Stop block; 306, Spring; 4, Pushing structure; 401, Connecting sleeve; 402, Second guide shaft; 403, Connecting plate; 404, Second guide groove; 405, Slide groove; 5, Guide post; 6, Guide sleeve; 7, Mounting hole. Detailed Implementation

[0028] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments of the present invention can be combined with each other. The technical solutions of the present invention will be further described below with reference to the accompanying drawings of the embodiments. The present invention is not limited to the specific embodiments described below.

[0029] It should be understood that the same or similar reference numerals in the accompanying drawings of the embodiments correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "front," "rear," "left," "right," "top," and "bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms describing positional relationships in the accompanying drawings are for illustrative purposes only and should not be construed as limiting this patent. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0030] Example 1

[0031] Existing molds for synchronous pulleys generally have draft angles, which cause deviations in the axial dimensions of the pulley, affecting its meshing accuracy with the synchronous belt, reducing transmission efficiency and stability, and failing to meet the requirements of high-precision equipment. Therefore, a synchronous pulley mold without draft angles was designed, as follows:

[0032] As shown in Figures 1-5, a non-draft mold for a synchronous pulley includes a moving module 1, a fixed module 2 on one side of the moving module 1, and an enclosure structure 3 on the moving module 1. The enclosure structure 3 includes a turntable 301 and a first guide groove 302. The turntable 301 is rotatably connected to the moving module 1. The turntable 301 is provided with multiple first guide grooves 302. Multiple sliders 304 are slidably connected to the moving module 1. One end of the slider 304 is fixedly connected to a first guide shaft 303. The first guide shaft 303 extends into the interior of the adjacent first guide groove 302 and is slidably connected to the turntable 301. The other end of the slider 304 is fixedly connected to a stop block 305. Adjacent stop blocks 305 abut against each other. The fixed module 2 is provided with a pushing structure 4.

[0033] The moving module 1 is equipped with multiple springs 306. One end of the spring 306 is fixedly connected to the adjacent slider 304, and the other end of the spring 306 is fixedly connected to the moving module 1. Therefore, when the second guide shaft 402 and the second guide groove 404 are separated, the slider 304 can be placed in a specific position under the action of the spring 306, so that the second guide shaft 402 can enter the interior of the second guide groove 404 when the mold is closed.

[0034] The multiple first guide grooves 302 are arranged in a circular array about the rotation center of the turntable 301. There is a certain angle between the orientation of the first guide grooves 302 and the sliding direction of the slider 304. Therefore, when the multiple first guide grooves 302 move at the same time, the multiple sliders 304 can also slide at the same time.

[0035] The cross-section of the slider 304 is dovetail-shaped, which can prevent the slider 304 from detaching from the inside of the moving module 1 and allow the slider 304 to slide only in a specific direction. One end of the multiple stops 305 abuts against the fixed module 2, and the other end of the multiple stops 305 abuts against the moving module 1, thus forming the die-casting cavity of the synchronous pulley.

[0036] The pushing structure 4 includes a connecting sleeve 401 and a second guide shaft 402. The connecting sleeve 401 is fixedly connected to the fixed module 2. The center of the turntable 301 and the center of the connecting sleeve 401 are on the same straight line. Two second guide shafts 402 are fixedly connected to the connecting sleeve 401. The two second guide shafts 402 are arranged in a circular array about the center of the connecting sleeve 401. Two connecting plates 403 are fixedly connected to the turntable 301. The two connecting plates 403 are arranged in a circular array about the center of the turntable 301. The connecting plates 403 are provided with a first... Two guide grooves 404 are arranged in a circular array about the center of the turntable 301. The second guide shaft 402 extends into the interior of the adjacent second guide groove 404 and is slidably connected to the connecting plate 403. The turntable 301 can be rotated by the movement of the second guide shaft 402 at the inclined position in the middle of the second guide groove 404. The moving module 1 is provided with a sliding groove 405, which can limit the movement trajectory of the connecting plate 403. The connecting plate 403 and the sliding groove 405 are slidably engaged.

[0037] Four guide pins 5 are fixedly connected to the moving module 1, and four guide sleeves 6 are fixedly connected to the fixed module 2. During the mold closing process, the guide pins 5 are inserted into the guide sleeves 6 to position the fixed module 2 and the moving module 1, thereby improving the mold closing accuracy. The guide pins 5 are inserted into the adjacent guide sleeves 6 and slide with the guide sleeves 6.

[0038] The moving module 1 has four mounting holes 7, so the moving module 1 can be installed and fixed. The stationary module 2 has four mounting holes 7, so the stationary module 2 can be installed and fixed.

[0039] Working principle:

[0040] After the mold is closed, adjacent stops 305 will abut against each other, one end of multiple stops 305 will abut against the fixed module 2, and the other end of multiple stops 305 will abut against the moving module 1. The protrusion in the middle of the fixed module 2 will engage with the moving module 1 to form the die-casting cavity of the synchronous belt pulley, so as to realize the die-casting of the synchronous belt pulley.

[0041] After the synchronous belt is die-cast, during the mold opening process, the moving module 1 will move away from the fixed module 2. During the movement of the moving module 1, the connecting sleeve 401 will move, and the movement of the connecting sleeve 401 will drive the two second guide shafts 402 to move. When the second guide shafts 402 move at an inclined position in the middle of the second guide groove 404, the connecting plate 403 slides inside the slide groove 405. The two connecting plates 403 move synchronously, driving the turntable 301 to rotate. The rotation of the turntable 301 abuts against the movement of multiple first guide shafts 303 inside the first guide groove 302. The movement of the first guide shafts 303 drives the slider 304 to move. The slider 304 drives the stop 305 to move away from the die-cast synchronous belt pulley, so that the multiple stop 305 does not contact the die-cast synchronous belt pulley, realizing the subsequent removal of the synchronous belt pulley. Since the multiple stop 305 moves away from the synchronous belt pulley, the demolding of the synchronous belt pulley can be achieved without draft angle, meeting the manufacturing requirements of high-precision die-casting of the synchronous belt pulley.

[0042] In this design, the block 305 of the non-draft mold actively and synchronously retracts radially inward during the mold opening process via the turntable 301, the first guide groove 302, the first guide shaft 303, and the slider 304, completely detaching from the side wall of the synchronous pulley after molding. This avoids the need to design draft angles on the side wall of the part, and helps to improve the geometric accuracy and dimensional consistency of the product.

[0043] When the mold is closed, the stop blocks 305 abut against each other, and their two ends abut against the moving module 1 and the fixed module 2 respectively. Combined with the protrusion in the middle of the fixed module and the engagement with the moving module, a closed cavity with precise positioning is formed, which ensures the shape and size accuracy of the molded parts.

[0044] The connecting sleeve 401, the second guide shaft 402, the connecting plate 403, and the second guide groove 404 separate the linear motion of the moving module 1 and the stationary module 2 during mold opening. The motion is converted into the rotational motion of the turntable 301 by sliding the second guide shaft 402 in the inclined second guide groove 404. The demolding action is directly driven by the power of mold opening, without the need for an additional power source. This simplifies the mold structure, reduces costs, and improves the coordination and efficiency of the action.

[0045] After the mold opening is completed and the second guide shaft 402 disengages from the second guide groove 404, the elastic force of the spring 306 can automatically push the slider 304 and its stop block 305 back to the initial specific position, so that the second guide shaft 402 can accurately and smoothly re-enter the second guide groove 404 when the mold closes again, thus ensuring the reliability and continuity of the mold cycle operation.

[0046] Example 2

[0047] In this embodiment, the mold structure is basically the same as in Embodiment 1, except that the first guide groove 302 and the second guide groove 404 are designed as closed guide holes or precision holes with wear-resistant bushings. Open guide grooves easily accumulate plastic debris, dust, and grease, which can lead to poor movement, accelerated wear, and even jamming over time. Closed guide holes or bushing-equipped holes effectively isolate contamination, improve movement accuracy, reliability, and lifespan. The wear-resistant bushings can be made of bronze or high-hardness alloy steel for easy replacement.

[0048] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating this utility model, and are not intended to limit the implementation of this utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A draft-free die for a timing pulley, comprising a moving module, characterized in that: A fixed module is provided on one side of the moving module. The moving module is provided with an enclosing structure, which includes a turntable and a first guide groove. The turntable is rotatably connected to the moving module. The turntable is provided with multiple first guide grooves. Multiple sliders are slidably connected to the moving module. One end of each slider is fixedly connected to a first guide shaft. The first guide shaft extends into the interior of an adjacent first guide groove and is slidably connected to the turntable. The other end of each slider is fixedly connected to a stop block. Adjacent stops block abut against each other. The fixed module is provided with a pushing structure.

2. The non-draft die for a timing pulley according to claim 1, characterized in that: The moving module has multiple springs inside, one end of each spring is fixedly connected to an adjacent slider, and the other end of each spring is fixedly connected to the moving module.

3. A non-drafting die for a timing pulley according to claim 1, characterized in that: The first guide grooves are arranged in a circular array about the rotation center of the turntable, and there is a certain angle between the orientation of the first guide grooves and the sliding direction of the slider.

4. A non-drafting die for a timing pulley according to claim 1, characterized in that: The slider has a dovetail-shaped cross-section, with one end of each of the multiple stops abutting against the fixed module and the other end of each of the multiple stops abutting against the moving module.

5. A non-drafting die for a timing pulley according to claim 1, characterized in that: The pushing structure includes a connecting sleeve and a second guide shaft. The fixed module is fixedly connected to the connecting sleeve, and two second guide shafts are fixedly connected to the connecting sleeve. Two connecting plates are fixedly connected to the turntable. The connecting plates are provided with second guide grooves. The second guide shafts extend into the interior of adjacent second guide grooves and are slidably connected to the connecting plates. The moving module is provided with a sliding groove, and the connecting plates and sliding grooves are slidably engaged.

6. A non-drafting die for a timing pulley according to claim 5, characterized in that: The center of the turntable and the center of the connecting sleeve are on the same straight line, and the two second guide shafts are distributed in a circular array about the center of the connecting sleeve.

7. A non-draft die for a timing pulley according to claim 5, characterized in that: The two connecting plates are arranged in a circular array about the center of the turntable, and the two second guide grooves are arranged in a circular array about the center of the turntable.

8. A non-drafting die for a timing pulley according to claim 1, characterized in that: The moving module is fixedly connected to four guide posts, and the fixed module is fixedly connected to four guide sleeves. The guide posts are inserted into the interior of the adjacent guide sleeves and slide with the guide sleeves.

9. A non-drafting die for a timing pulley according to claim 1, characterized in that: The moving module has four mounting holes, and the stationary module has four mounting holes.

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